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Jezebels_couz Jezebels_couz is offline
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Default shunt/ current sense resistor question

On 12/2/20 9:50 AM, Ralph Mowery wrote:
In article , says...

In the process of finishing a 0-12 VDC @ 0-10 A switching power supply.
Fairly new at this and wanted to ask about the shunt resistor. It will
be in the ground line. Plans mentioned two options: either a custom
shunt made from constantan wire or similar, or simply two 5W 0.1 ohm
power resistors in parallel. Since I wanted to keep costs down, I am
going with the power resistors, but I have a concern: I will be running
12 gauge wire for the output lines, but when the ground wire reaches the
shunt, even the two resistors in parallel combined are far less than 12
gauge. Should I be concerned, or is the tiny resistor/ 12 gauge wire
distance (basically just for the 12 ga wire to resistor wire connection)
irrelevant to heating and losses?



The small wire of the resistors should handle it just fine. The main
reason for # 12 wire on the circuit is for the voltage drop.


Here's a diagram of what I was trying to explain. I wasn't sure I was
very clear, so hopefully the diagram will better relate:

https://i.imgur.com/pYSRxiX.jpg